Mr Schuck said he encountered hotel security guard Jesus Campos, who had been shot in the leg by gunman Stephen Paddock.

Mr Campos told the maintenance man to take cover.

“It was kind of relentless so I called over the radio what was going on,” said Mr Schuck.

“As soon as the shooting stopped we made our way down the hallway and took cover again and then the shooting started again.”

Soon afterwards, Paddock, 64, sprayed bullets upon a nearby crowd at the Route 91 country music festival, perched above in his suite on the 32nd floor of the Mandalay Bay hotel.

Paddock apparently took his own life after the attack, the deadliest mass shooting in modern US history, leaving 58 dead and 500 wounded.

According to CBS News, gunfire could be heard as Mr Schuck told a dispatcher on his radio: “Call the police, someone’s firing a gun up here. Someone’s firing a rifle on the 32nd floor down the hallway.”

It was unclear if hotel staff alerted police to the shooting.

The BBC has asked the Las Vegas Metropolitan Police Department and the Mandalay Bay hotel for comment.

Mr Schuck’s account adds more questions about why police were unaware of the shooting on the 32nd floor before Paddock opened fire on concert-goers below.

Police initially said Mr Campos, the injured security guard, interrupted the gunman as he was firing upon the crowd from his hotel suite.